X-ray fluorescence (XRF) is a convenient, nondestructive, rapid technique that is effective at identifying specific elements in a wide variety of matrices. There are ten elements regulated for their toxic effects world- wide. The challenge is that these ten elements are difficult or impossible to measure simultaneously at the regulated levels with traditional XRF or any other chemical or combustion technique. It is both difficult and expensive to limit the exposure risk to these toxins for medical, regulatory, and manufacturing teams. Two of the most difficult elements for XRF are cadmium (Cd) and antimony (Sb). In the proposed project, XOS will develop X-ray optics that can be integrated into commercial XRF systems. XOS already provides other x-ray optics for other medical, compliance, and research instruments. The team includes the world leaders in developing optics for and integrating optics into analytical systems. XOS will develop X-ray optics for Cd and Sb measurements that meet or exceed the regulated levels. The proposed optics is based on extending the capabilities of our successful, commercially available monochromatic optics and doubly-curved crystal (DCC) optics to higher energy ranges than are currently possible. Thus, they will retain the high-sensitivity and low-background advantages of the current DCC optics. The optics will be designed, developed, tested, and validated in the proposed project. The proposed new optics for Cd and Sb will be incredibly valuable to epidemiological studies, occupational exposure monitoring, and medical treatment teams, as well as manufacturers by using the optics in an XRF instrument which is accurate, reliable, nondestructive, simple-to-use, inexpensive, and compact. Such an optic-enabled instrument would have a positive impact on public health by rapidly identifying the source and level of risks, screening for toxicity, assessing levels in patients with related diseases (e.g., pulmonary or kidney disease), monitoring patients undergoing chelation therapy, conducting a heavy metal screen for people with an occupational exposure risk, and helping manufacturers and farmers eliminate these toxins. Further, the in-vitro detection of these trace metals could be compared to existing data sets in wider exposure studies such as the Genes, Environment and Health Initiative (GEI). This significantly increases the usefulness and marketability of the instrument. Because of the broad commercial applications, this will enable the production of lower-cost instruments for medical, environmental, and occupational exposure applications. Society will benefit from improved knowledge of the role of these metals which are linked to many respiratory, cardiovascular, renal, gastrointestinal, hematological, and musculoskeletal diseases (DHHS 1992, 1999). Use in bone, renal, heart, liver, etc. studies of other medical pathologies and in other fields such as forensic, atmospheric, geological, agricultural, chemical, pharmaceutical etc. will, over time, greatly broaden the medical, scientific, industrial, and, therefore, societal benefits. PUBLIC HEALTH RELEVANCE: The proposed project will develop the X-ray optics for cadmium and antimony to enable X-ray fluorescence to simultaneously measure the entire range of toxic elements normally monitored for occupational exposure, medical treatment, consumer products, and industrial uses with an instrument which is accurate, reliable, nondestructive, simple-to-use, inexpensive, and compact. Such an optic-enabled instrument would have a positive impact on public health by rapidly identifying the source and level of risks, screening for toxicity, assessing levels in patients with related diseases (e.g., pulmonary or renal disease, and reproductive or developmental effects), monitoring patients undergoing chelation therapy, conducting a heavy metal screen for people with an occupational exposure risk, and helping manufacturers and farmers eliminate these toxins from their products. Further, the in-vitro detection of these trace metals could be compared to existing data sets in wider exposure studies such as the Genes, Environment and Health Initiative (GEI), which significantly increases the usefulness and marketability of the instrument and, therefore, will enable the production of lower- cost instruments for medical, environmental, and occupational exposure applications.